Midge (Chironomidae)

Midge, in the drift all year, active in water between 33 and 75°F, and imitated at #18–24. Recorded from every region this map covers, across Michigan, Wisconsin, Virginia, North Carolina and Minnesota.

The smallest thing worth imitating and the most constant one: midges are in the water all year, with every month from January through December counting as peak, and an active band from 33 to 75 degrees that spans cold, cold-transitional, cool and warm water. Hooks run 18 to 24. The larva is thread-thin and often bright red or olive, living in the sediment and taken all winter — a red or black Zebra Midge is a larva imitation and it fishes twelve months a year. The pupa hangs vertically just under the film, and that is where most midge feeding actually happens; a slow rise with no visible fly is almost always a pupa take. Adults are two-winged, no bigger than a comma on the page, and raft together in mating clusters, which is what a Griffith's Gnat imitates — a cluster, not one insect. When nothing else explains rising fish, it is midges.

#18–24Hook size
33–75°FWater, active
all yearAvailable
3Life stages fished

Subbasins with trout water where it is on record: 129 of 326 across the 6 states this map draws.

See the trout water on the live map → Every reach coloured by water temperature — the water these hatches come off.

What it is

Midge · Chironomidae · larva → pupa → adult

Midges: the smallest thing worth imitating and the most constant. Larvae are thread-thin and often bright red or olive; pupae hang vertically in the film; adults are two-winged and no bigger than a comma on the page.

The only thing hatching in January and still hatching in July. When nothing else explains rising fish, it is midges.

When it hatches

The months below are this site's shared calendar, which covers 8 regions at once. In southeast Minnesota the state's own source says January–October, and the Minnesota page is built on that instead.

In the water twelve months a year, which is why the panel in the app ranks it below anything with a season.

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peak shoulder not recommended

Water conditions

The band is a water temperature, not an air temperature, and it is the range in which this insect is worth fishing — for a mayfly that is the emergence window; for a scud or a midge it is simply the range trout will still eat one in.

33°F 75°F

Active from 33°F to 75°F. On this map that is cold, cold-transitional, cool, warm water — the band crosses 3 of the three breaks the river colours use. Breaks at 58, 64 and 70°F.

Stages

What the insect is doing, and what that means for what you tie on.

Stage	What it is
larva	A worm-like larva in the sediment, taken all winter. A red or black zebra midge is a larva imitation and it fishes twelve months a year.
pupa	The pupa hangs suspended just under the film, and this is where trout do most of their midge feeding. A slow rise with no visible fly is almost always a pupa take.
adult	Adults raft together on the surface in mating clusters — which is what a Griffith's Gnat imitates, a cluster rather than one insect.

Matching flies

8 patterns in this book imitate the Midge, across its stages. Which one to tie on follows the stage the water temperature says it is in — the app makes that call on a live reading; this page lists the whole set.

Where to find it right now

The rivers with a page here that sit in this insect's regions, with a USGS gauge reporting water temperature. This list is re-ranked against the reading each gauge is sending now and today's date, so it is live — the fallback below it, if the readings do not arrive, is each river's measured July mean.

Regional presence

Regions, not collection records. This insect is recorded from the coarse regions below; nobody has surveyed which named river it has been caught on, and this page will not pretend otherwise.

northern lower Michigan MI
southern lower Michigan MI
the Upper Peninsula MI
the Wisconsin driftless WI
northern Wisconsin WI
the Virginia mountains VA
the North Carolina mountains NC
southeast Minnesota MN

Rivers in these regions with a page here

Related hatches

Same family, or overlapping this one's calendar on the same water.

Open the trout map →Every trout stream near you, coloured by today's water temperature.